Gas-valve



1. A. HOFF.

GAS VALVE.

APPLICATION man MAR- 4. 1920.

Patented Dec. 7, 1920',

' Application filed March 4 1920. Serial No. 363,340.

N TED sms; P ATi-ENT; op um" JOHN A. HOFF, or enrcneo, ILLINOIS, ASSIGNOR To PURE cmomc COMPANY, or f cnrcaeo, ILLINOIS, a ooaromrron or rumors.

C GAS- VAnvE.

To all whom it may concern: Be it known that I, JOHN cago, in the county'of Cook and State of the following is a specification.

My invention relates to valves fol-controlling delivery of fluid under pressure, such] for example asthe valves used on tanks containing carbonic acid gas approximating a pressure of one thousand. pounds to the square inch.. I am to provide a simple and easily assembled valve structure wherein gas or other fluid pressure cannot bring about a condition interfering with the working of the valve stem, while at the same time gas pressure is availed of to keep the valve'thoroughly packed against any leakage when in use. -I furthermore aim to provide a form of coupling in the valve-operating connec-" tions which, while permitting the desired axial play of parts inthe interests of the self-packing characteristic above mentioned, will at the same time possess exceptional strength so that no matter how hard the valve may turn no breakageof thejcoupling willoccur inside. the valve body, and the same istrue as to-capacity of the coupling to withstand the strain when force is misapplied in a valve-opening direction when the valve is already lifted to the limit or in a valveclosing direction when the valve is already fully seated.

In the drawings which accor?anying form part of this specificatiom; 'gure 1.

represents a longitudinal section of the complete valve structure; Fig. 2 represents a.

' similar section taken at right an les to the Fig. 1 section and showing a di erent sort of'packing; Fig. 3 is a horizontalsection'. taken on the line 33 of Fig. 1; Figs. 4 and Y 5 are perspective views of a piston and coupling member and of the valve plug; and Fi 6 is a sectional illustration of a modifie construction. a

The numeral 2 designates the body or casing of the valve structure'which has. an interior valve-seat 3 and a screw-threaded bore 4 above said valve seat. The numeral 5 designates the valve plug which is screwthread'ed to engage said bore and carries a block of aluminum 6 to engage the valve seat. Beyond this screw-threaded bore of the casing there is a smooth bore 7 of an en- Specification of letters Patent.

pose of compressing the packing.

larged' diameter in "which a piston works-p" also serving as one member of the valve-op Patented Dec. 7,1920;

erating'coupling. The piston'isdesignated v by thenumeral Sand it has a conical upper or backportion 9- (Fig. '1) from whichex:

tends the stem 10. 1 Packing material 11 is received in the casing above this conical portion of the piston and a screw cap 12 is applied to the casing, the stem of the piston extending loosely through this cap and its squared end-portion being surrounded by a circular flange 12 on the cap interiorly formed for enga' ement of a spanner.

The piston is ormed with a pair'of integral jaws 13 which are of generally segmental shape, and the valve-plug is formed with a cross-head 14: relatively narrow at the middle and widening toward each end.

Asv here shown the opposite sides oflthis' cross-head present arcuate surfaces lying back-to-back, and the jaws of the piston are correspondingly shaped except for beingv truncated at their middle ,ortions as most clearly shown in Fig. 3. he idea is to em-- ploy all the metal possible within the circle of these parts andso dispose it as to supply the greatest strength for the turning of the valve plug by the piston. In this connection it will be notedithat the driving contact is confined to the outer thick portions of the cross-head, and it will be obvious that a much stronger coupling is provided than would be the case if a simple. flat blade was employed working loosely 1n a slot. g

In putting the parts together'it'is-notnecessary to apply any force for the. ur-

latter can be loosely put in and the screw I cap simply turned home, that is until it abuts against the outer end of the casing,-'-

the valve-plug having of course been inmaterial into intimate contact with the walls of the casing. The packing material not being confined between an internal shoulder of the casing and a gland and the valve stem with its piston being separate from the valve plug and axially movable relative thereto and the valve-stem-piston being in a chamber to which the gas has access, it is not necessar to rely at all upon the tightening of any g and in order to initially compress the packing. The piston "responds instantly to the gas pressure and i acts as a ram to compress the packing, and the heavier the pressure the more dense and tighter does the packin become to subserve its function of eflectua y sealing the valve structure. j V I In my construction acking of loose charig. 1) and 0 any sort of material that will pack may be employed with good results (I have even found that sand will serve the purpose). However, a satisfactory practice is to employ composition washers such as those that may be found upon the market made of canvas and rubber, and it is desirable to include an ingredient of lubricant such as graphite to guard against so-called freezing of the packing to the metal surfaces with which it is in contact. I have shown two such washers in Fig. 2, designatedl5. I have also found it desirable to employ a leather washer 16 around the stem under the screw cap particularly where loose packing is employed,

so as to prevent the latter from being forced in between the stem and the walls of the openin 1n the screw cap. While the conical formation at the back of the piston is ad-,

fibrous washer.

the flat back surface of the piston a leather washer 21 is inter osed. Another leather washer 22 is pre erably put behind the I here preferably employ a flat-metal spring 23 which snugly fits the smooth bore of the casing, hearing at its outer end against the screw cap and at its' inner end against a metal washer 2 I may here mention that brass is employed for all of the metal parts of the structure (except merely the seat-block of aluminum) on account of its not being acted upon deleteriously by the as, and I may here advert to the subject 0 my novel form of coupling to state that it makes entirely practicable the employment of brass alone notwithstanding its higher ductility and consequent reduced strength for transmitting motion or resisting strain as compared with some other metals. Thus, as beforev pointedout, I contrive to retain the maximum of bulk in the engaging parts of the coupling and to apply the turning force in such manner as to take full advantage of the maximum thickness of'the coacting formations which are integral with the respective members between which motion is being transmitted, or resistance encountered.

I claim:

In a valve structure of the character described, a valve screw-plug and a detached stem and piston, the latter and the valve plug having interlocking formations by which to turn the valve plug by the stem while allowing relative axial movement between these parts, said formations comprising a diametrical cross-head on one of said parts thickening from its middle both ways and a pair of jaws on the other part receiving said cross-head between them and being of generally se ental shape complemental to the crossead, driving engagement between said jaws and the cross-head being confined to the outerthickened portions of the latter. a

- JOHN A. HOFF. 

